Nasty Vibration
 

The Monte has developed a very bad vibration in high gear. Changed driveshafts and the problem seemed to lessen temporarily, but it's back as bad as before. The driveshaft is straight. Dad can barely hold the shifter back in 4th as he crosses the finish line. We are taking the tranny apart to see if the mainshaft is bent or ???. Can a ring gear be out of balance? We are sending the clutch and disk away to get balanced. Axles ???.

Any help would be appreciated as we're really scratching our heads on this one.

Many thanks in advance!!

Re: Nasty Vibration
 

Just random thoughts, but 1, Make sure rear hasn't moved (string-measure both sides, center of front whl. to center of back whl.) 2, Pinion bearing going bad, or something moved inside rear? Good luck....WJ

Re: Nasty Vibration
 

Might have lost a wheel weight or two???????

Re: Nasty Vibration
 

Several years ago, I had a front wheel/tire out of balance at Scribner that caused my vision to blur so bad that I could not see the scoreboards.
It shook everything in the car.
I had Joe Archer re-balance and cleared it up.

Re: Nasty Vibration
 

Rear bushing in tranny or main shaft bearing.

Re: Nasty Vibration
 

Had a similar problem years ago. I had the drive shaft rebalanced, changed the bushing in the trans tail shaft housing, and also had the front and rear wheels rebalanced. Problem was still there, bad vibration about the last 300' of the track. Ended up breaking the trans case across the bell housing. I put a new Dedenbear trans case in the car and the problems was still there. By this time the rear tires needed replacing and bingo the problem went away. Smooth as glass with the new tires. Before this problem started the car had sat in the garage for two months while freshing the engine. I had neglected to put the car up on jack stands and I guess the rear tires got flat spots. Won't make that mistake again.

Re: Nasty Vibration
 

I had the same issue on my 5speed mustang, it would vibrate so bad that it would jump out of gear as soon as i pulled into gear. It was my mainshaft that was bent. I took it to work and put it on jig and realize it was bent!!! I junked it and put a new one in, and never had the problem again.

Re: Nasty Vibration
 

Mike I had the same thing last year. I could not hold the shifter in high gear. Pilot bearing came out in pieces when we dropped the can. Ed

Re: Nasty Vibration
 

I had a similar situation when a couple of bell housing bolts had backed out earlier this year, sounds simple but it can happen.

Re: Nasty Vibration
 

Housing is centered. Pinion bearing feels good and rotates smooth, but 3rd member is coming out tonight, so we'll see. Thanks